In known hub members, the internally toothed annular gear and the brake disk are formed of one piece which has the disadvantage that these parts influence one another, as a result of heat development therein and the resulting warpage. Also the entire member must be made of a material appropriate for the most highly stressed part.
The basic purpose of the invention is to overcome these deficiencies, namely to produce a device of the type described above, in which hub member, annular gear and/or brake disk have little or no influence on one another with respect to heat generation and resulting warpage. A further purpose is to diminish material costs.
The basic purpose of the invention is attained by means of a device characterized in that the rotating hub member includes an annular gear and/or a brake disk consisting of at least two components made from different materials. When the annular gear is made of material of a high quality, the hub member is releasably connected thereto. In one development of the invention the teeth of the annular gear are arranged on further annular means which are radially spaced from the hub member other than for the presence of a supporting land whereby to provide a barrier against the transfer of heat from one component to the other and further to prevent the distortion resulting therefrom. On the other hand, it may be advantageous as an alternative or as an addition to separate the brake disk from the remaining device. In this respect the heat development on the brake disk and the radiation of same must be carefully controlled. In this connection it may be desirable to mount the brake disk releasably onto the hub member and for this purpose it will be advantageous if the brake disk also is arranged on an annular support which is excepting for a supporting land arranged in radially spaced relationship to the hub member. In mounting the brake disk it will be advantageous if said brake disk or its annular support is provided with a flange which serves to secure the rim onto the hub member. From the standpoint of installation and service, it will be desirable to locate such mounting flange externally of the apparatus for easy access.
In order to assure a good installation of the device, the invention is further so developed that the brake disk is separate from the hub member and the brake disk is provided with means for securing the rim. The invention may be advantageously still further developed by making the member which is provided with the teeth of the annular gear separate from the hub member, which construction is of special advantage in that the member which carries the teeth of the annular gear can consist of different material from that of the hub member. In this way, the teeth of the annular gear can be constructed of a material which can carry the desired high stress, while the remaining parts, substantially the hub and the brake disk, can be made of a material more appropriate to the function of these parts. The invention has a special meaning for electric vehicles in which for each wheel which must be driven one motor is provided to which advantageously the axle is flanged.
Further advantages and characteristics of the invention can be taken from the following description.
The invention will be described in connection with exemplary embodiments which are illustrated in FIGS. 1 to 4.